The key point of asymmetric catalytic synthesis is how to design and synthesize chiral catalysts with high selectivity and catalytic activity, wherein chiral ligand is the source of asymmetric inducement and control produced by a catalyst. The C2 type chiral bisoxazoline ligands have been widely applied in asymmetric reactions catalyzed by metals, such as asymmetric cyclopropylation reaction, intramolecular Wacker-Type cyclization reaction, asymmetric oxidation reaction of olefin, and intramolecular [2+1] ring addition reaction, and the like, due to their specific structures. During the past 30 years, a large numbers of chiral oxazoline ligands have been developed, especially those with various chiral side chains. Among others, axial chiral side chain has been widely used in the ligand due to its unique rigid structure. After years of studies, BINAP, an axial chiral ligand containing binaphthyl structure, has been applied successfully in industrially producing optical active compounds.

The successful industrial application of BINAP, promotes the application of axial chirality in the design and synthesis of ligands. Oxazoline ligands containing axial chiral side chains have been developed successively and applied in various asymmetric reactions catalyzed by metals.
After searching in the prior art, E. J. Corey et. al. (Tetrahedron Letters, Vol. 36, No. 48, pp. 8745-8748, “The First Enantioselective Synthesis of the Chemotactic Factor Sirenin by an Intramolecular [2+1] Cyclization Using a New Chiral Catalyst”) proposed a design concept of axial chiral ligand incorporating two relative large groups on the ortho position of biaryl axis. Although stable axial chirality can be obtained through their steric hindrance, the rotatable angle of biphenyl is also limited, i.e., the dihedral angle is limited. However, it has been confirmed that the dihedral angle influences the catalysis activity and selectivity of asymmetric catalytic reaction. Thus, design and synthesis of novel axial chiral ligand is among the most interesting research topics of organic chemistry.